How to Seal Preserve Jars
It is very important, when canning preserves, to make sure that the jars are sealed properly. The entire process involves placing food in glass jars and heating the filled jars until hot enough that microorganisms, which can spoil food, are destroyed. It is this heating process that also secures the lids on the jars by forming a vacuum seal, preventing air from getting to the food inside and bringing contaminating microorganisms with it. Does this Spark an idea?
Things You'll Need
- Preserving recipe
- Ingredients called for in the recipe
- Boiling water canner (or a large, deep saucepot with a lid) and a rack
- Glass preserving jars with new lids and bands
- Tongs or jar lifter
- Funnel
- Spatula
- Damp cloth
- Canner rack
Instructions
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1
Read your preserving recipe and gather the necessary ingredients. Make sure you are using the correct jar size.
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2
Check your jars, lids and bands for nicks, cracks, uneven rims, sharp edges or other defects. These can cause breakage or prevent proper sealing.
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3
Wash the jars and the lids in hot, soapy water; then rinse well and make sure the bands are dry.
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4
Heat the jars and lids in hot but not boiling water until you're ready to use them if your recipe requires hot food to be put into the jars. Putting hot food into hot jars will prevent the jars from cracking. Always leave the bands at room temperature.
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5
Prepare a boiling water canner by filling it halfway with water and keeping the water at a simmer (with the pot's lid on) until the jars are added. If you're using a deep stockpot or saucepot instead, make sure it is large enough to surround and immerse your jars with water by one to two inches. The water must be able to boil rapidly around the jars with the pot's lid on.
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6
Follow the recipe instructions using fresh, high-quality ingredients.
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7
Remove a hot jar from the hot water using tongs or a jar lifter; fill the jar with the prepared food using a funnel, but leave ¼ to ½ inch headspace.
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8
Remove air bubbles, if your recipe directs you to, by carefully sliding a spatula between the jar and the food to release any air that has become trapped. Repeat this sliding motion around the jar two to three times.
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9
Use a damp cloth to clean jar rims of food residue; then remove a lid from the hot water and center it on the jar. Apply the band and adjust it until the fit is fingertip-tight. (Don't use anything but your hands.)
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10
Repeat Steps 7 to 9 with remaining prepared food and jars.
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Place filled, lidded jars in the canner or pot with a canner rack, if possible. Otherwise just place them in the pot and make sure the water is boiling around them and on top of them (that they stay submerged). Put the lid on the canner/pot, bring the water to a rolling boil and begin counting down the processing time directed in your recipe.
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Turn off the heat when the processing time has concluded, remove the canner/pot lid, and let the jars stand in the canner/pot for five minutes. Then remove the jars from the canner/pot with a jar lifter or tongs, and set them on a towel, where you'll leave them for 12 to 24 hours. Do not tighten or loosen the bands, as this will affect the sealing process as the jars cool.
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13
Check the lids for tight seals by making sure they don't flex up or down when the lid centers are pressed. Remove the bands and try to lift off the lids with your fingertips. You should not be able to do so. If you CAN lift the lids with your fingertips, the lids have not sealed, and the food inside must be refrigerated or reprocessed.
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Tips & Warnings
Use only jars and lids/bands made especially for canning with tempered glass and a thicker rim than, say, a commercial mayonnaise jar. Canning jars come in 8 ounce, pint or quart sizes and can have regular or wide mouth openings. The latter is best for larger pieces of vegetables (like pickles) or fruit (like pear halves). They are sold in boxes of 12, and each jar comes with a two-piece lid: a cap that seals to the rim of the jar and a band or screw cap that holds the cap down. You can reuse your jars, but always use new two-piece lids.
